Influence of coal mechanical properties and water content on generation characteristics of coal particles

Coal particles have a great importance in the production of coalbed methane. To reveal the relationship between the coal mechanical properties and the coal particles characteristics generated by the coal samples with different coal rank, coal failure experiments in the natural state and water-saturated state under triaxial compression are performed. The effects of coal rank, coal mechanical properties and water content on the characteristics of coal particles generated are investigated. The results show that the water-saturated sample has a lower compressive strength than the corresponding natural sample. Coal with different rank shows various fracturing modes after failure. Compared with the natural sample, the water-saturated sample generates more amount of coal particles. As coal rank increases, the amount of coal particles shows a 'U' shape trend, while there is a negative exponential correlation between the amount of coal particles and the compressive strength of coal. [Received: June 3, 2020; Accepted: April 10, 2021]